(1) Field of the Invention
The present invention relates to novel pyrazole derivatives and selective herbicidal composition containing as an active ingredient one or two or more of said pyrazole derivatives.
(2) Description of the Prior Art
Hitherto, extensive researches and development on herbicides have been conducted for long years to provide varieties of herbicides for practical use. These herbicides have contributed to saving the labors for controlling weeds and to increasing production of agricultural and horticultural crops.
Yet, it is still required at present to develop novel drugs having more superior herbicidal characteristics. Especially as to agricultural and horticultural herbicides, it is desirable that they selectively control intended weeds with a lower dosage without adversely effecting on cultivated crops. However, the drugs which have been already known do not necessarily exhibit such favorable herbicidal characteristics.
The present inventors have found, in the course of researches on herbicidal characteristics of various organic compounds to develop useful herbicides, that the compounds of the formula (I) given below exhibit excellent herbicidal action against true grasses (true grasses and umbrella plants) and various broadleaf weeds without showing substantial adverse effects on useful crops such as cultivated crops of, for example, corn and sorghum, and, thus, completed the invention.